Crystal structures, mechanical and electronic properties of tantalum monocarbide and mononitride

Abstract

With density functional theory, structural, electronic and mechanical properties of tantalum monocarbide (TaC) and tantalum mononitride (TaN) of the tungsten carbide (WC), nickel arsenide (NiAs), rock salt (NaCl), cesium chloride (CsCl), and zinc blende structure were investigated, respectively. Our results indicate that TaN of the WC-type structure (TaN-WC), which has a large bulk modulus, Young’s modulus, and a small Poisson’s ratio, is the most stable one among the considered compounds. The theoretical hardness of TaN-WC is 37.1 GPa, which indicates that TaN-WC is a potential candidate structure to be one of the ultraincompressible and hard materials.